IOS-涂鸦

 //
 //  PaintView.m
 //  IOS_0224_涂鸦
 //
 //  Created by ma c on 16/2/24.
 //  Copyright © 2016年 博文科技. All rights reserved.
 //

 #import "PaintView.h"

 @interface PaintView ()

 //存放每次触摸的完整路径
 @property (nonatomic, strong) NSMutableArray *path;

 @end

 @implementation PaintView

 - (NSMutableArray *)path
 {
     if (_path == nil) {
         _path = [NSMutableArray array];
     }
     return _path;
 }

 /*方法一*/
 /*
 //确定起点
 - (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
 {
     UITouch *touch = [touches anyObject];
     CGPoint startPoint = [touch locationInView:touch.view];

     //每次开始触摸，就新建一个数组来存放这次触摸的所有点
     NSMutableArray *pathPoints = [NSMutableArray array];
     [pathPoints addObject:[NSValue valueWithCGPoint:startPoint]];
     //添加每次触摸的所有点形成的路径到path中
     [self.path addObject:pathPoints];

     [self setNeedsDisplay];
 }
 //连线
 - (void)touchesMoved:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
 {
     UITouch *touch = [touches anyObject];
     CGPoint currentPoint = [touch locationInView:touch.view];

     //取出这次路径对应的数组
     NSMutableArray *pathPoints = [self.path lastObject];
     [pathPoints addObject:[NSValue valueWithCGPoint:currentPoint]];

     [self setNeedsDisplay];

 }
 //结束点
 - (void)touchesEnded:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
 {
     UITouch *touch = [touches anyObject];
     CGPoint endPoint = [touch locationInView:touch.view];

     //取出这次路径对应的数组
     NSMutableArray *pathPoints = [self.path lastObject];
     [pathPoints addObject:[NSValue valueWithCGPoint:endPoint]];

     [self setNeedsDisplay];

 }

 - (void)drawRect:(CGRect)rect {
     CGContextRef ctx = UIGraphicsGetCurrentContext();

     for (NSMutableArray *points in self.path) {
         for (int i = 0; i < points.count; i++) { //一条路径

             CGPoint point = [points[i] CGPointValue];

             if (i == 0) {
                 CGContextMoveToPoint(ctx, point.x, point.y);
             }else{
                 CGContextAddLineToPoint(ctx, point.x, point.y);
             }
         }
     }

     CGContextSetLineCap(ctx, kCGLineCapRound);
     CGContextSetLineJoin(ctx, kCGLineJoinRound);
     CGContextSetLineWidth(ctx, 5);
     CGContextStrokePath(ctx);
 }

  */

 /*方法二*/
 - (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
 {
     //1.获得当前触摸点
     UITouch *touch = [touches anyObject];
     CGPoint startPoint = [touch locationInView:touch.view];
     //2.创建一个新的路径
     UIBezierPath *startPath = [UIBezierPath bezierPath];

     startPath.lineWidth = ;
     startPath.lineCapStyle = kCGLineCapRound;
     startPath.lineJoinStyle = kCGLineJoinRound;
     //设置起点
     [startPath moveToPoint:startPoint];
     //3.添加路径到数组中
     [self.path addObject:startPath];

     [self setNeedsDisplay];

 }

 - (void)touchesMoved:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
 {
     UITouch *touch = [touches anyObject];
     CGPoint currentPoint = [touch locationInView:touch.view];

     UIBezierPath *currentPath = [self.path lastObject];
     [currentPath addLineToPoint:currentPoint];

     [self setNeedsDisplay];
 }

 - (void)touchesEnded:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
 {
     [self touchesMoved:touches withEvent:event];

 }

 - (void)drawRect:(CGRect)rect
 {
     [[UIColor redColor] set];
     for (UIBezierPath *path in self.path) {
         [path stroke];
     }
 }

 - (void)clear
 {
     [self.path removeAllObjects];
     [self setNeedsDisplay];
 }

 - (void)back
 {
     [self.path removeLastObject];
     [self setNeedsDisplay];
 }

 @end